Reliability evaluation for ensuring the uninterrupted system operation is an integral part of dependable system development. Model-based safety analysis (MBSA) techniques such as Hierarchically Performed Hazard Origin and Propagation Studies (HiP-HOPS) have made the reliability analysis process less expensive in terms of effort and time required. HiP-HOPS uses an analytical modelling approach for Fault tree analysis to automate the reliability analysis process, where each system component is associated with its failure rate or failure probability. However, such non-state-space analysis models are not capable of modelling more complex failure behaviour of component like failure/repair dependencies, e.g., spares, shared repair, imperfect coverage, etc. State-space based paradigms like Markov chain can model complex failure behaviour, but their use can lead to state-space explosion, thus undermining the overall analysis capacity. Therefore, to maintain the benefits of MBSA while not compromising on modelling capability, in this paper, we propose a conceptual framework to incorporate complex basic events in HiP-HOPS. The idea is demonstrated via an illustrative example. For more information check the following papers: https://doi.org/10.1007/978-3-030-32872-6_8 https://doi.org/10.1109/TR.2019.2923893 https://doi.org/10.1109/ACCESS.2019.2941566

1. 1
A Conceptual Framework to Incorporate Complex
Basic Events in HiP-HOPS
Sohag Kabir, Koorosh Aslansefat, Ioannis Sorokos, Yiannis Papadopoulos, and Youcef Gheraibia
Email: k.aslansefat-2018@hull.ac.uk

2. 2
Table of Content
What we are going to discuss
Introduction
Brief Introduction for Reliability Modeling Challenges and HiP-HOPS Tool
Proposed Approach
A Conceptual Framework to Incorporate Complex Basic Events in HiP-HOPS
Numerical Results
Numerical results for reliability vs. time
Conclusion
A conclusion and suggestions for future research works

3. 3
Brief Introduction on HiP-HOPS
Synthesized
FMEA
Design
Optimization
Hierarchical System
Evaluation
Synthesized
Fault Trees
HiP-HOPS: Hierarchically Performed - Hazard Origin and Propagation Studies
[3]
Papadopoulos, Y., McDermid, J.A.: Hierarchically performed hazard origin and propagation studies. In: International Conference on
Computer Safety, Reliability, and Security. pp. 139-152. Springer (1999).

4. 4
Capability of HiP-HOPS
Why is automation needed?
System Design Model
What effect does the fault have?

5. 5
Capability of HiP-HOPS
Why is automation needed?
Fault Tree
Synthesis
Algorithm
System failures
Component failures
System model
Failure annotations
of components
Global view of
failure+ =

6. 6
Research Challenges
01
02 04
03
01.
Complex Basic
Events
02.
Non-Exponential
Failure Distributions
04.
Incorporation with
HiP-HOPS
03. Considering Real-Time Observations

7. 7
Proposed Approach
A Conceptual Framework to Incorporate Complex Basic
Events in HiP-HOPS
 Annotation
Synthesis and Analysis
Real-Time Evaluation

8. 8
Proposed Approach
A Conceptual Framework to Incorporate Complex Basic
Events in HiP-HOPS
Annotation
 Synthesis and Analysis
Real-Time Evaluation

9. 9
Proposed Approach
A Conceptual Framework to Incorporate Complex Basic
Events in HiP-HOPS
Annotation
Synthesis and Analysis
 Real-Time Evaluation

10. 10
Proposed Approach
A Conceptual Framework to Incorporate Complex Basic
Events in HiP-HOPS
 Annotation
 Synthesis and Analysis
 Real-Time Evaluation

11. 11
Example of Annotation and Considering Complex BE
HIP-HOPSTool

12. 12
Assumptions
At the beginning, system is always operational
There is no common cause failure in the system
During the mission repair is not possible
The failure of the components can obey non-
exponential probability distribution functions.
● Probability Distribution Function of Failures

13. 13
Numerical Results
Reliability Evaluation + Real-Time Observation
Kabir, S., Azad, T., Walker, M., Gheraibia, Y.: Reliability analysis of automated pond oxygen management system. In: 18th
International Conference on Computer and Information Technology (ICCIT) (2015).

14. 14
Numerical Results
Reliability Evaluation + Real-Time Observation

15. 15
Numerical Results
Reliability Evaluation + Real-Time Observation

16. 16
Numerical Results
Reliability Evaluation + Real-Time Observation
Reliability of Battery and Power systems with
and without observation

17. 17
Numerical Results
Reliability Evaluation + Real-Time Observation
Reliability of the whole system with and
without observation

18. 18
Conclusion
In this paper, a framework for incorporating the SMP-based complex behaviour modelling of system
components in HiP-HOPS has been presented.
The SMP-based basic event modelling supports distribution-independent analysis of system.
The proposed framework enables us to perform evidence-based systems analysis at runtime.
The current approach focuses on the quantitative analysis part of the HiP-HOPS approach. In the
future, the qualitative analysis aspects can be added for considering the complex behaviour of BEs.

19. 19
Acknowledgements
Dependability Engineering Innovation for Cyber Physical Systems (CPS)

20. 20
References
Papadopoulos, Y., McDermid, J.A.: Hierarchically performed hazard origin and propagation studies. In: International
Conference on Computer Safety, Reliability, and Security. pp. 139-152. Springer (1999).
Kabir, S., Azad, T., Walker, M., Gheraibia, Y.: Reliability analysis of automated pond oxygen management system.
In: 18th International Conference on Computer and Information Technology (ICCIT) (2015).
Distefano, S., Longo, F., Trivedi, K.S.: Investigating dynamic reliability and availability through state-space models.
Computers & Mathematics with Applications 64(12), 3701-3716 (2012).
Kim, D.S., Ghosh, R., Trivedi, K.S.: A Hierarchical Model for Reliability Analysis of Sensor Networks. In: 2010
IEEE 16th Pacific Rim International Symposium on Dependable Computing. pp. 247-248 (2010).
Zeller, M., Montrone, F.: Combination of component fault trees and Markov chains to analyze complex, software-
controlled systems. In: 2018 IEEE 3rd International Conference on System Reliability and Safety (ICSRS). pp. 13-
20 (2019).
Nguyen, T.A., Min, D., Choi, E., Tran, T.D.: Reliability and availability evaluation for cloud data center networks
using hierarchical models. IEEE Access 7, 9273-9313 (2019).

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